How Our Numbers Have Changed

Why anything moved at all

No table anywhere says what incorporating Niwot would cost a household. It has to be built — from the county assessor’s parcel roll, Census survey data, the sales-tax receipts of a comparable town, and a budget nobody has run yet. That takes months. The vote does not wait.

So we published early and kept working. Each revision below is a figure that was estimated becoming one that is derived: an assumption replaced by a measurement, or a number that could not be reproduced from its own inputs rebuilt so that it could.

We are not claiming the numbers have stopped moving. We are claiming something narrower and checkable: they are derived rather than asserted, each is reproducible from a published command, and a figure cannot quietly change on one page while staying put on another. The full derivation, with its error bars sets out how uncertain each input is, and which one carries most of that uncertainty. It is the Census margin on Niwot’s own household income, and it is not close.

The revisions

In date order. Some raised the cost we publish and some lowered it; they are listed the same way either way, because a page that sorted them by whether they suited us would not be worth reading.

1. 12 September

   What incorporation costs a typical household

   $60 a month→$65 a month

   Our model assumed Niwot households buy less telephone and internet service because Niwot has fewer offices than the town we benchmarked against. That is a claim about businesses, applied to households. Removing it raised the figure by about $4 a month. We found it and published the higher number the same day.

2. 14 September

   What incorporation costs a typical household

   $65 a month→$60 a month

   Four more, found in the same week the checks that catch them were built. The largest: we had been treating a per-person spending figure as per-household. We were also taxing groceries, which Niwot would exempt, and charging the full 2.5% downtown where the municipal tax replaces an existing 1% district tax.

3. 14 September

   The range across households

   $41 to $92 a month→$44 to $92 a month

   The two ends of that range had been computed on different assumptions — the floor from a more pessimistic spending estimate, the ceiling from the central one. Put on one basis, the floor rose by $3. Nothing was recomputed and the typical figure did not move; the range stopped answering two questions at once. This one came from outside: a campaign that disagrees with us had reproduced our table and could not get our floor out of it. They were right that it was not derivable as published.

4. 16 September

   Household spending, by type of home

   one figure for every dwelling→$473 a year for a house, $244 for a condominium

   Until this date every home in Niwot carried the same household spending tax, whether a $340,000 condominium or a $3.2 million house — overstating the smallest households and understating the largest. The split is measured: Census household size by structure type and the county voter roll independently agree that a condominium household is 0.48 of the town average. The typical figure rose to $63, because the typical dwelling is a house and a house holds more people than average.

5. 21 September

   Share of town revenue paid by Niwot households

   48.3%→50.1%

   One budget line — use tax — was split between households and businesses at a ratio nobody had derived. Deriving it from the line’s own components moved households up, so we now say households carry slightly more of the town’s revenue than we had been. It does not change what anybody pays.

6. 27 September

   How far sales tax can fall before the budget is in trouble

   28% before the annual surplus reaches zero→19.8%, permanently, before accumulated reserves run out

   A change of measure, not a correction of arithmetic. The 28% was exact when it was written: in 2030 the budget modelled $2,319,000 of sales tax against a $649,000 surplus. The budget then moved to setting road reserves aside every year as an expense rather than letting them accumulate as surplus — the more cautious treatment — which takes that surplus to about $12,000 and leaves any measure built on it meaningless. The replacement is a harder test: how far sales tax would have to fall and stay fallen, every year to 2040, before the town had spent its accumulated reserves. The smaller number is the tougher test, and we were slow to move our own pages onto it.

7. 28 September

   The range across households

   $28 to $94 a month→$28 to $108 a month

   Two defensible methods spread the same town-wide spending total across homes, and they disagree about the top of the range far more than the bottom. We now publish the central estimate where they agree and the higher figure where they genuinely disagree, which raises the ceiling by $14 and leaves the floor and the typical figure alone. The rule applies at every point rather than end by end — otherwise it becomes a way to pick the convenient number.

8. 28 September

   Private-road costs, Countryside and Cottonwood Park Condos

   $398 and $1,015 per home→$756 and $590 per home

   The two associations share Countryside Drive, and the county’s roads workbook can attribute a road to only one owner, so it gave the whole drive to one of them. Now split by length, as the committee’s own survey does. The total pavement is unchanged to the square foot — this moved who carries the cost, not the cost.

9. 28 September

   Chance the town’s reserves go negative at some point by 2040

   3.4%→2.6%

   The pro forma rebuilt its stress-test simulation and its results table moved, but the summary beneath the table went on quoting the older figure. Nothing about the budget changed; a paragraph was left behind when the table above it moved.

What stops this happening quietly

A figure moving is not the problem. A figure moving in one place and not another is — that is how a campaign ends up with two numbers for the same thing and no idea which one a resident is holding.

Every published figure that has ever been superseded is recorded, with the date and the reason, in a file that runs against every page, paper, handout and letter each time thesite is built. If a retired figure reappears anywhere a reader can reach, the site does not build — not as a warning, as a failure. Where a document has to quote an old figure — a change record like this one, or a filing that is frozen as submitted — that exception is written down with its reason rather than waved through.

The same applies to the models. The household cost, the road costs, the district levies and the budget stress test each have a script that regenerates them, and a check that fails if a published figure has drifted from what the model produces.

What we have not changed

The two tax rates on the ballot — a 2.5% sales tax and a 4-mill property levy — have never moved. Neither has the structure of the budget they fund. What has moved is our estimate of what those rates cost a particular household, which is a different question and a harder one.

Figures filed with the Election Commission are frozen as submitted. Where an estimate has since moved away from a filed figure we say so rather than quietly restating it; the divergence is set out in the methodology paper.